As a rule, a conventional shoe is composed of an upper, or rather an external covering, and a sole to which said upper is to be joined. This type of operation must provide the use of an insole, peripheral to which the edge of the upper is turned-up and therefore stably fixed, for example by means of gluing. Traditional insoles, for instance, can be rigid or soft and are made up of a flat surface in certain anatomical cases, and moreover are provided with a containment structure that peripherally duplicates the shape of the sole of the foot.
In the case of a sporting shoe, vice versa, a rigid insole is not generally used, but rather provision is only made for the interposition of a layer of material insert or fubbett covered with the fabric to be placed on the inside of the housing defined by a sole provided peripherally with a side, or alternatively, providing the integration of a layer of soft material of the shock absorber type in the sole, to then finally join the upper to said sole according to usual techniques.
A process is also known for producing footwear that provides a sole or a stratified insert that is obtained by joining single layers of material on top of each other, often with different technical specifications to each other. The same applicant proposed a first teaching, which had as an object an insole sewn onto the upper or of the removable type. As stated by the redactor, in essence, the suggestion consists in the connection of three insoles (inserts) of which the first is a rubbery elastic material, the second is special material with high elasticity and recall and finally the third material is leather. The insole manufactured in this way, that is to say layered, is mainly proposed as an integrating element of a normal light shoe, in which the layer of leather forms the sole and is sewn directly to the upper. Among the applications, an insert with a high level of elasticity and comfort is provided that is to be introduced into a normal shoe, or alternatively as an insert to be sewn directly to the upper for light, relaxation, sporting or driving footwear.
Among the most common drawbacks of conventional footwear is the fact that adequate acclimatizing is not permitted, above all in the support area of the sole of the foot. This circumstance, as is already known, determines the onset of excessive sweating with the frequent formation of unpleasant odours. Also, it should not be forgotten that the inadequate ventilation of the foot, together with the effect of sweating permits the proliferation of micro-bacteria and fungus, a rather common problem that is not easily resolved. Finally, also due to the effect of a lack of ventilation, insufficient comfort is observed, which causes the phenomenon of steamchill.
The companies in this sector have, therefore, for some time being orientated in this direction, with the main object of finding innovative solutions and often improved solutions from the technical point of view, with reference to pre-existing solutions.